Medically reviewed by Steffini Stalos, DOKey TakeawaysA rheumatoid factor test checks for an antibody that can be a marker for rheumatoid arthritis. It is one part of diagnosis.Not everyone with a ...

A rheumatoid factor (RF) test detects rheumatoid factor, a type of antibody (proteins that fight off harmful substances) in your blood. RF antibodies sometimes attack healthy cells and tissues, ...

Rheumatoid factor (RF) is a type of antibody, an immune system protein that helps the body fight foreign substances like bacteria and viruses, called antigens. Antibodies, also known as ...